The present invention relates generally to construction systems and methods for use in new and existing structures and, more specifically, to composite systems and methods for anchoring walls to footings, foundations, roofs, and slabs.
In new construction and retrofit and repair applications it is often necessary to strengthen or reinforce masonry, concrete, and timber walls such that they are capable of withstanding flexural loads caused by, for example, the wind or seismic activity. It is also often necessary to strengthen or reinforce the positive connection between such walls and footings or slabs, enabling the walls to withstand and transfer shear loads as well. Masonry, concrete, and timber walls are typically strengthened using steel reinforcing members, such as reinforcing bar (“rebar”). For example, rebar may be inserted into the cavities of the concrete masonry units (“CMUs” or “cinder blocks”) of a masonry wall, or in the collar joints of a brick structure. The CMU cores may then be filled with grout. The rebar may extend vertically downward and mate with dowel holes drilled in the footing or it may extend vertically upward and mate with dowel holes drilled in the slab. Although marginally effective, in retrofit and repair applications these systems and methods may require the face shells of the CMUs to be temporarily removed. Thus, such systems and methods may be obtrusive, labor-intensive, and expensive.
More desirable systems and methods for strengthening or reinforcing masonry, concrete, and timber walls involve the use of high-strength composite materials. The flexural and shear load capability of a wall may be increased by adhering a thin composite fiber sheet or laminate impregnated with an epoxy resin or polymer to its surface. Typical composite laminates include glass, carbon, or aramid fibers. Such composite materials are 5 to 10 times stronger per unit weight than comparable traditional materials. These systems and methods, however, do little to increase the strength of the connection between a wall and a footing, foundation, floor, roof, or slab because they do not interface the wall with its supporting structure. Thus, what is needed are systems and methods utilizing composites for strengthening and reinforcing the positive connection between reinforced or unreinforced walls and footings or slabs. Further, what is needed are systems and methods that are unobtrusive, relatively simple to implement, and inexpensive.